The present invention generally relates to an improved gearshift lever for a steering column and, more particularly, to such a gearshift lever having an electrical switch at an operative end of the gearshift lever.
A gearshift lever is typically provided in a motor vehicle, such as an automobile, to control a gear box or transmission connecting an engine with driven wheels. The gearshift lever can extend from the vehicle floor or a steering column of the vehicle. When extending from the steering column, the gearshift lever typically has a shape with compound bends to optimally position the ends of the gearshift lever. Often, an electrical switch, such as a push-button type switch, is provided at the operative or free end of the gearshift lever so that the driver can easily activate or deactivate a particular device. When such a switch is provided, wires are routed along the length of the gearshift lever from the attachment end of the gearshift lever at the steering column to the switch located at a handle or knob on the operative end.
One method of forming such a xe2x80x9cswitchedxe2x80x9d column gearshift lever is to drill a central passage along the length of a steel rod. The rod is deburred to decrease the risk of damage to the wires due to burrs formed in the drilling operation. The rod is then bent to a desired shape. The rod then undergoes a washing operation to decrease the risk of contamination during subsequent molding operations. The rod is then placed in a mold and a polymeric covering is formed about the rod. A hand grip portion or knob forming a seat for the electrical switch is either integrally molded with the covering to the operative end or secured to the operative end before or after the molding operation. The switch is secured to the knob with wires extending through the central passage to the attachment end where they are connected to auxiliary components of the particular device which the switch controls so that the operator can control the device with the switch.
While such a method forms suitable switched steering-column gearshift levers, it has several disadvantages. For example, the drilling, deburring, bending, and washing operations are extremely labor intensive. Additionally, the metal rods can cause extensive damage to the molds when the bends are out of tolerance and therefore do not properly cooperate with the molds. Moreover, the metal rods can cause extensive contamination of the molds if they are not properly cleaned prior to insertion into the molds.
Accordingly, there is a need in the art for a steering-column gearshift lever which is produced with an increased number automatic operations, which causes decreased amounts of mold damage and contamination during molding operations, is relatively inexpensive to produce, is relatively lightweight, and is highly reliable to operate.
The present invention provides a steering-column gearshift lever for a motor vehicle which overcomes at least some of the above-noted problems of the related art. According to the present invention, a steering-column gearshift lever includes, in combination, a tube comprised of a polymeric material and forming a conduit from an operative end to an attachment end, an electrical switch supported by the operative end of the tube, and wires connected to the electrical switch and passing through the conduit from the operative end to the attachment end. In a preferred embodiment of the present invention, the tube has compound bends and the conduit and wires follow the compound bends. The present invention provides a steering-column gearshift lever which is formed by highly automatic and repeatable molding operations, eliminates mold damage due to improper bending of tubes by eliminating bending operations, and reduces metal contamination during molding operations by reducing the number of metal components.
According to another aspect of the present invention, a steering-column gearshift lever comprising, in combination, a tube comprised of a polymeric material and forming a pocket at an attachment end and a metal insert secured to the attachment end and extending into the pocket. The metal insert is sized and shaped for mechanical cooperation with components auxiliary to the lever. In a preferred embodiment the metal insert is secured to the tube with an interference fit therebetween.
According to another aspect of the present invention, a steering-column gearshift lever comprises, in combination, a tube of polymeric material and forms a conduit from an operative end to an attachment end. The tube includes a main portion and a cover portion adapted to cooperate with the main portion to form the conduit. A covering of polymeric material extends over at least a portion of an exterior surface of the main and cover portions of the tube. The tube and the covering are formed in separate molding operations. In a preferred embodiment, the main and cover portions are adapted for injection molding and cooperate when placed together to seal the conduit during subsequent molding of the covering and prevent covering material from bleeding into the conduit during molding of the covering. The present invention provides a steering-column gearshift lever permits the use of separate structural and covering materials which are formed by separate injection molding operations.
From the foregoing disclosure and the following more detailed description of various preferred embodiments it will be apparent to those skilled in the art that the present invention provides a significant advance in the technology and art of steering-column gearshift levers. Particularly significant in this regard is the potential the invention affords for providing a high quality, reliable, light weight, low cost assembly. Additional features and advantages of various preferred embodiments will be better understood in view of the detailed description provided below.